Intercontinental dispersal of HIV-1 subtype B associated with transmission among men who have sex with men in Japan.

Transmission clusters of HIV-1 subtype B uniquely associated with the epidemic among men who have sex with men (MSM) in East Asia have recently been identified. Using the Los Alamos HIV sequence database and the UK HIV drug resistance database, we explored possible links between HIV MSM epidemics in East Asia and the rest of the world by using phylogenetic and molecular clock analyses. We found that JP. MSM. B-1, a subtype B MSM variant that accounts for approximately one-third of the infections among Japanese MSM, was detected worldwide, in the United Kingdom (n = 13), mainland China (n = 3), the United States, Germany, Canada, and Taiwan (n = 1 each). Interestingly, 10 United Kingdom samples plus two from Germany and the United States formed a distinct monophyletic subgroup within JP. MSM. B-1. The estimated divergence times of JP.MSM.B-1 and the latter subgroup were similar to 1989 and similar to 1999, respectively. These dates suggest that JP. MSM. B-1 was circulating for many years in Japan among MSM before disseminating to other countries, most likely through global MSM networks. A significant number of other Asian MSM HIV lineages were also detected in the UK HIV drug resistance database. Our study provides insight into the regional and global dispersal of Asian MSM HIV lineages. Further study of these strains is warranted to elucidate viral migration and the interrelationship of HIV epidemics on a global scale. IMPORTANCE We previously identified several transmission clusters of HIV-1 subtype B uniquely associated with the epidemic among men who have sex with men (MSM) in East Asia. Using the Los Alamos HIV sequence database and the UK HIV drug resistance database, we explored the possible interplay of HIV MSM epidemics in the different geographic regions and found previously unrecognized interrelationships among the HIV-1 epidemics in East Asia, the United Kingdom, and the rest of the world. Our study provides insight into the regional and global dispersal of Asian MSM HIV lineages and highlights the importance of strengthening HIV monitoring efforts and the need for implementing effective control measures to reduce HIV transmission on a global scale.